Drilling traction system and method

ABSTRACT

A traction system for connecting and/or disconnecting pipe during well drilling is disclosed. The traction system of the present disclosure is installed above a rotating control device or blowout preventer and may be used with a continuous circulation device. The traction system uses a traction assembly that holds tension on a pipe to lift or hoist the pipe and that has two or more elements in contact with the pipe that spin around the pipe to rotate the pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/431,549, filed Dec. 8, 2016, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the described embodiments. Accordingly, it should be understood that these statements are to be read in this light and not as admissions of prior art.

In the well drilling industry, including without limitation in the oil and gas industry, a well may be drilled to facilitate installation of a completion system at a surface end of the well in order to extract oil, natural gas, and/or other subterranean resources from the earth and/or to inject substances downhole. Such a well may be located onshore or subsea, depending on the location of the desired extraction and/or injection coordinates.

Various mechanisms exist for drilling wells, including but not limited to conventional systems and methods for connecting/disconnecting bodies or tubulars for use in advancing the depth of the wellbore drilled downhole. For example, one such conventional connection technique includes periodically (intermittently) making up each connection between two sections or stands of drill pipe. A conventional rig requires use of a large structure (e.g., derrick), in and out of which the operator hoists the pipe, of such a height as to accommodate hoisting a length or stand of pipe vertically, end-on-end, such that the pipe section can be connected at its bottom end to the top end of a connected pipe string below. The drive for such hoisting is provided by a top drive or a kelly located at or near the upper end of the derrick. A top drive will screw into the top connection of the pipe providing torque and lift to the drill string. Although a top drive requires a torque generator to move up and down with the pipe, it can provide force and torque over the entire length of travel (e.g., 90 feet), in contrast to a kelly, which is limited to a single pipe length (e.g., 30 feet). A conventional rig also requires use of a large floor area (e.g., rig floor), where most of the tools for breaking and making connections are located, at a significant height off the ground or base structure from which connected pipe string may be lowered downhole. These features result in the conventional drilling rigs being large structures that can be costly to mobilize and demobilize.

Another example of a conventional connection technique involves continuously (i.e. non-intermittently) drilling using snubbing units with rotary drives such as described in U.S. Patent Application Publication No. 2014/0124267. However, such continuous drilling systems still require either a hoist (hence top drive and derrick) or hydraulic actuators longer than a single stand (e.g., 90 feet).

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of embodiments of the present disclosure, reference will now be made to the accompanying drawings in which:

FIG. 1 depicts a cross-sectional view of a traction system installed above a rotating control device or blowout preventer in accordance with one or more embodiments of the present disclosure; and

FIG. 2 depicts a cross-sectional view of a traction system installed above a rotating control device or blowout preventer and below a continuous circulation device system in accordance with one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of the present invention. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

This discussion is directed to various embodiments of the disclosure. The drawing figures are not necessarily to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.

When introducing elements of various embodiments of the present disclosure and claims, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, any use of any form of the terms “connect,” “engage,” “couple,” “attach,” “mate,” “mount,” or any other term describing an interaction between elements is intended to mean either an indirect or a direct interaction between the elements described. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. The use of “top,” “bottom,” “above,” “below,” “upper,” “lower,” “up,” “down,” “vertical,” “horizontal,” and variations of these terms is made for convenience, but does not require any particular orientation of the components.

Certain terms are used throughout the description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function, unless specifically stated.

The present disclosure relates to a traction system that, in its various embodiments, may be used in a variety of applications and industries in which it may be necessary to drill into a rock formation for a borehole or well, including oil, gas, water, onshore, offshore, subsea, new wells and well workovers, for example. The traction system of the present disclosure can eliminate the need for a derrick and/or rig floor on a drilling or workover rig and/or if used with a continuous circulation system may significantly mitigate the transients associated with connections.

Referring now to FIG. 1, a cross-sectional schematic of a drilling traction system 100 located above a rotating control device (RCD) or blowout preventer (BOP) 400 in accordance with one or more embodiments of the present disclosure is shown. The traction system 100 is mounted above the BOP 400 and uses a traction assembly 10 capable of holding tension on a pipe 300 to lift or hoist the pipe 300, and that has elements in contact with the pipe that spin around the pipe to rotate the pipe 300. The pipe 300 can be any of a variety of types of pipe or tubular, including without limitation drill pipe, coiled tubing, bottom hole assembly, casing, tubing, hardware, or the like.

As illustrated, the traction assembly 10 is a rotating chain system; however, in embodiments, the traction assembly 10 may be another type of traction device for lifting the pipe in and out and/or rotating the pipe. For example, the traction assembly 10 may be an integral device (e.g., chain, tread, track, electromagnetic device, or the like) and/or may include individual elements (e.g., links, blocks, wheels, rollers, balls, track or tread segments, or the like). In the illustrated rotating chain system, a set of two chains is shown; however, more chains may be used, for example, three, four, or five or more chains. Any blocks or protrusions on a coiled tubing-type rotating chain system, or any individual elements of any other type of traction assembly 10, may be on an assembly to track across pipe size changes, including connections.

As illustrated in FIG. 1, the traction assembly 10 may include coiled tubing type chains or chain drive, with or without blocks or protrusions, to provide the lift for the pipe. The traction assembly 10 may be mounted on a rotary assembly or rotary drive 160, which supplies power and torque to the traction assembly 10, such as for example via bearings 180, and is directly or indirectly mounted to the frame 20. A swivel 140 may be used to transmit electric, hydraulic, and/or signal to the rotating assembly. Any blocks on a chain of a traction assembly 10 may be modified as necessary to transmit torque such that the pipe 300 can be moved and rotated from a fixed position.

The traction assembly 10 transmits axial force or load to the outer wall of pipe 300 while rotating about an axis 50 of a well. During rotation of the traction assembly 10, the pipe 300 can move in a direction along the axis 50, while the support structure or frame 20 remains stationary, i.e., does not move in the axial direction.

A set of spinning breakout tools, power tongs, or iron roughneck 30 can be used to disconnect or make connections between any two pieces of pipe, including without limitation around a fluid connection that could provide continuous circulation. The iron roughneck 30 mounted on top of the traction system 100 of the present disclosure allows the pipe 300 connections to be broken or remade without the requirement for personnel at height. Slips 80 can be used to hold the pipe in place when stationary.

In operation, a new section of pipe is lifted and swung into place, for example from pipe racks, with a hydraulic arm/actuator (not shown). The new pipe is connected to a mud flow line 120 prior to being put in place. A swivel (not shown) for the mud flow line 120 may be attached to the pipe 300 (with a breakout machine at ground or base level) before the pipe is lifted off the ground or base level.

Referring now to FIG. 2, a cross-sectional schematic of a drilling traction system 100 located above a rotating control device (RCD) or blowout preventer (BOP) 400 and below a continuous circulation device system 200 in accordance with one or more embodiments of the present disclosure is shown. In the illustrated embodiments, the continuous circulation device system 200 will allow mud to be circulated during connections.

In operation, by way of illustrative non-limiting example, a procedure for breaking a connection may include locating a connection (for example between an upper end of a lower pipe and a lower end of an upper pipe) just above lower seal 40, energizing the upper seal 60 and lower seal 40, each or both of which may be inflatable seal(s). Power tongs or iron roughneck 30 can be used to break the connection with the lower pipe held by the traction (e.g., chain) assembly 10. After switching the mud circulation from the upper pipe to the mud flow line 120, the upper connection can be pulled to a location above a non-return valve 90 (e.g., a flapper valve, a one-way valve, a check valve, ball valve, poppet valve, or the like). The valve 90 can be closed to seal, the upper seal 60 can be de-energized, the pipe pulled.

A procedure for making a connection may reverse a corresponding procedure for breaking a connection. Accordingly, based on the above, an illustrative non-limiting example procedure for making a connection may include lowering the upper pipe downhole with bottom end between upper seal 60 and closed non-return valve 90, energizing the upper seal 60, opening the valve 90, lowering the upper pipe to a location below the valve 90, switching the mud circulation from the mud flow line 120 to the upper pipe, using the power tongs or iron roughneck 30 to make the connection with the lower pipe, already downhole and held by the traction (e.g., chain) assembly 10, and de-energizing the upper seal 60 and lower seal 40. With effective control the system could be made with zero discharge capability.

By using a short length drive system that grips the side of the pipe and removing the need for a hoist to pull the pipe out of the well, the total height of the rig can be significantly reduced. Using remote mounted breakout tools, the rig floor also can be removed, significantly reducing the footprint of the rig as well.

Accordingly, with the drilling traction system of the present disclosure, there may be no need for a derrick or a rig floor. For a land rig, the derrick can be eliminated, and for an offshore rig, the derrick can be eliminated or its height profile substantially reduced. Likewise, the size and weight of any hydraulic swivel used to deliver fluid to the top of the pipe can be substantially reduced.

Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims. 

What is claimed is:
 1. A drilling traction system for connecting a pipe to a pipe string, comprising: a frame; a traction device configured to rotate in axial contact with the pipe, thereby to apply force to and rotate the pipe; and a rotary drive disposed on the frame and configured to drive the movement of the traction device.
 2. The drilling traction system of claim 1, wherein the frame is mounted above one or more of a rotating control device and a blowout preventer.
 3. The drilling traction system of claim 2, wherein the frame is mounted below a continuous circulation system.
 4. The drilling traction system of claim 1, wherein the pipe comprises one or more of drill pipe, coiled tubing, a bottom hole assembly, casing, tubing, and hardware.
 5. The drilling traction system of claim 1, wherein the traction device comprises one or more of a chain, a tread, a track, and an electromagnetic device.
 6. The drilling traction system of claim 1, wherein the traction device comprises two or more elements each configured to move in axial contact with the pipe, thereby to apply force to and rotate the pipe.
 7. The drilling traction system of claim 6, wherein the two or more elements are links, blocks, wheels, rollers, balls, track segments, or tread segments.
 8. The drilling traction system of claim 6, wherein the two or more elements include blocks or protrusions on a tracking assembly configured to track across a change in an outer diameter of the pipe.
 9. The drilling traction system of claim 1, wherein the traction device comprises two or more chains.
 10. The drilling traction system of claim 1, wherein the pipe is axially moveable while the frame remains axially stationary during the rotation of the traction device.
 11. A method for breaking a pipe connection, the method comprising: locating between a lower seal and an upper seal a pipe connection joining a lower pipe and an upper pipe; energizing the lower and upper seals; and using a rotary drive, rotating a traction device in axial contact with the lower pipe to rotate the lower pipe and break the connection between the lower pipe and the upper pipe.
 12. The method of claim 11, wherein at least one of the lower and upper seals is an inflatable seal.
 13. The method of claim 11, wherein the traction device comprises one or more of a chain, a tread, a track, and an electromagnetic device.
 14. The method of claim 11, wherein the traction device comprises two or more elements each configured to move in axial contact with the pipe, thereby to apply force to and rotate the pipe.
 15. The method of claim 11, further comprising: switching mud circulation from the upper pipe to a mud flow line; and pulling the upper pipe to a location above a non-return valve; closing the valve; de-energizing the upper seal; and pulling the upper pipe away from the lower pipe.
 16. A method for making a pipe connection, the method comprising: lowering an upper pipe to a location below an upper seal and above a closed non-return valve; energizing the upper seal; opening the valve; lowering the upper pipe to a location below the valve; switching mud circulation from a mud flow line to the upper pipe; and using a rotary drive, rotating a traction device in axial contact with a lower pipe to rotate the lower pipe and make the connection between the lower pipe and the upper pipe.
 17. The method of claim 16, wherein at least one of the lower and upper seals is an inflatable seal.
 18. The method of claim 16, wherein the traction device comprises one or more of a chain, a tread, a track, and an electromagnetic device.
 19. The method of claim 16, wherein the traction device comprises two or more elements each configured to move in axial contact with the pipe, wherein each element is a link, a block, a wheel, a roller, a ball, a track segment, or a tread segment.
 20. The method of claim 19, wherein at least one of the two or more elements includes a block or a protrusion to accommodate a change in an outer diameter of the lower pipe. 